Radial shaft seals that are designed for use in sealing the main rotating shaft of vehicle air conditioner compressors, superchargers, power steering pumps, and engine crankshafts may utilize multiple sealing elements designed such that a first sealing element facing the fluid or gas to be sealed is an elastomer. The elastomer generally has sufficient flexibility and resilience to provide a seal against the shaft. A second stiffer and more resistant sealing element is generally positioned behind and in tandem with the elastomeric seal such that an axial gap is provided between the sealing edge of the stiffer wear-resistant seal and the back sealing edge of the more resilient elastomeric sealing element. The second sealing element is generally made from a polytetrafluoroethylene (PTFE) or filled PTFE material.
Generally in the art, the different seal structures are typically assembled together and then are clamped together in a unit using a crimping and bonding process. In such a process, a rubber element is crimped between two metal casings to form a seal. The PTFE component is also typically crimped or bonded to the rubber component. It is known in the art to utilize a flat PTFE washer or preformed conical-shaped structure that is bonded or clamped to form the overall seal.
It is an object of this invention to provide a lower cost product and method by minimizing the material usage of a PTFE component. It is also an object to eliminate one of the metal casing structures required in various clamped sealed configurations, as well as to eliminate additional manufacturing steps that are currently utilized in the art.